< Previous | Contents | Next >
Truth is black and white, at least as far as C++ is concerned. You can represent true and false with their corresponding keywords, true and false. You can store such a Boolean value with a bool variable, as you saw in Chapter 1. Here’s a quick refresher:
bool fact = true, fiction = false;
This code creates two bool variables, fact and fiction. fact is true and fiction
is false. Although the keywords true and false are handy, any expression or
39
40 Chapter 2 n Truth, Branching, and the Game Loop: Guess My Number
value can be interpreted as true or false, too. Any non-zero value can be interpreted as true, while 0 can be interpreted as false.
A common kind of expression interpreted as true or false involves comparing things. Comparisons are often made by using built-in relational operators. Table 2.1 lists the operators and a few sample expressions.
Table 2.1 Relational Operators | |||
Operator | Meaning | Sample Expression | Evaluates To |
equal to | 5 == 5 | true | |
5 == 8 | false | ||
!= | not equal to | 5 != 8 | true |
5 != 5 | false | ||
> | greater than | 8 > 5 | true |
5 > 8 | false | ||
< | less than | 5 < 8 | true |
8 < 5 | false | ||
>= | greater than or equal to | 8 >= 5 | true |
5 >= 8 | false | ||
<= | less than or equal to | 5 <= 8 | true |
8 <= 5 | false | ||